Though they didn't kill Miakid, someone/something else did.
Likely, but not necessarily. Quote and Curly wounded Miakid, but we don't know what happened after that. Curly simply can't remember. Quote well, Curly says 'Do you remember anything?'...
Basically there's the possiblity that Quote or Curly could have finished Miakid off although I don't think right away, although something prevents them from remembering anything between that time and when they wake up much later.
It is possible, but I would disregard any notion of this being for the benefit of the already heavily reduced Mimiga population.
Even with their "heavily reduced" population, they somehow manage to wage war upon the earth, seemingly for some significant period of time...
So how is this possible? What exactly IS the war? How long does it last?
The way Kazuma, Booster, even Sue talk about it... it must be significant to the earth. Which makes me think there were more than just a few frenzied mimgas left...
Perhaps there were MANY frenzied mimigas left? If the Red Flower can cause the undead to rise again... perhaps the same can be said for the Frenzied Mimigas. Although there were MANY frenzied mimgas... we know that there are only a few untainted Mimigas left...
He would have to. The robots would have labeled him as an enemy the moment he took the crown for himself.
Depends...
"Finally, one man got the ODemon CrownO in his possession. The robots' work was done, and the island fell silent. But that was just the beginning of the tragedy."
He could have fooled the robots, their mission was to acquire the demon crown... once it was completed they were finished. Any remaining threats could have been sent to the labyrinth by Misery [as shown by several robots rotting in the labyrinth] or even sent to the Core. Yes, it's possible they were sent to destroy the core... but it's also possible they were fooled into gathering there. You saw how many, many,many, many bodies were in there. I don't think they were ALL killer robots. In fact I think a lot of them were probably just regular robots. They were probably clueless as to what was happening before the Core came out and started to wipe them out.
Although it's up to you to decide how it really happened...
The point is to have the human think so that the robots don't have to.
That's one way to see it. But, it depends on who was in charge of the robots actions.